Before he was shot dead Dec. 1 in Terrytown, football standout Joe McKnight possibly cut off his admitted killer, Ronald Gasser, while driving either before or on the Crescent City Connection, Jefferson Parish Sheriff Newell Normand said Tuesday (Dec. 6) after Gasser's arrest.

The sheriff also revealed McKnight had a gun in the vehicle, but he said McKnight never took the gun out of the car and that Gasser never knew of that gun's existence when he fired his own weapon from inside his car, hitting McKnight.

The details came as Normand addressed the public for the first time after Gasser was arrested Monday night (Dec. 5) on a count of manslaughter.

The incident possibly began with McKnight's vehicle cutting Gasser's car off, Normand said. In response, Gasser pursued McKnight in a heated "road rage" encounter involving shouting and swerving through traffic that led to the intersection of Behrman Highway and Holmes Boulevard. There, McKnight exited the gray Audi Q7 SUV he was driving, approached Gasser's blue Infiniti G37, and was shot fatally.

Normand said investigators used video footage from dozens of business surveillance cameras along the way, and testimony from dozens of people, to try to reconstruct the chase.

The sheriff said both Gasser and McKnight were "driving erratically," with one witness singling out McKnight specifically as driving erratically across the bridge.

Around then, Normand said McKnight possibly cut Gasser off. According to a statement given to police, Gasser said he was "irritated" by the cut-off and "set out after Mr. McKnight," Normand said. What followed was a heated cat-and-mouse road pursuit in which Gasser and McKnight "engaged each other many times" as they exited the Gen. de Gaulle Drive off ramp and turned right onto Behrman Highway.

All the while, Gasser and McKnight were shouting at each other through open windows, Normand said, "on each other's tails, cutting in front of one another, zipping around vehicles, on and on and on."

The two then came to a stop at a red light at Behrman and Holmes, with Gasser positioned in front of McKnight. McKnight pulled around to the side of Gasser's car, which was then "hemmed in" on all sides by McKnight's and other vehicles, Normand said. Arguing between the two men continued.

At that point, McKnight exited the Audi and went up to Gasser's car, both still arguing, Normand said. During this final exchange of words, Gasser pulled his gun from between a seat and the console inside his car, Normand said. Gasser fired three rounds into McKnight as he was bent over to meet Gasser at eye-level outside Gasser's passenger window, killing McKnight.

Normand did not go into additional details of Gasser's statement at the press conference, other than to say "it is replete with statements about his fear of McKnight making threatening statements and otherwise."

"That's why on Thursday evening, only faced with, and only having Mr. Gasser's statement, that we thought it best that an arrest not be made for strategic reasons, until we could get other witnesses," Normand said. He added that investigators only found six witnesses Thursday evening, none of whom saw the shooting -- other than a witness who Normand said gave a false statement.

Following the shooting, Gasser exited his vehicle still holding the gun to see what happened to McKnight, Normand said. Gasser then turned toward a Naval officer at the scene, who advised Gasser to stand down by suggesting "he did not want to shoot a military officer," Normand said. Gasser complied and surrendered to deputies when they arrived around 3 p.m., as the military officer assisted deputies in attempting to resuscitate McKnight.

Four days later, by 5 p.m. Monday, investigators had compiled enough evidence to draft an arrest warrant, Normand said. Gasser was booked into Jefferson Parish jail on one count of manslaughter Monday night.

"What we had were two adult males engaged in unacceptable behavior, (who) did not understand how to deal with conflict resolution, and this thing went to a point that unfortunately led to incredibly tragic consequences over bad driving behavior and bad spoken words," Normand said.

Normand noted that a gun was found in the Audi driven by McKnight, which was actually his stepfather's vehicle. Gasser was not aware McKnight had a gun in the SUV, Normand said.

Addressing why Gasser was booked with manslaughter, as opposed to a more serious count of second-degree murder or negligent homicide, Normand said the sheriff's office found the current evidence to warrant only manslaughter. But that charge could change if additional evidence is found and presented to the Jefferson Parish District Attorney's Office, which may take several weeks to file formal charges, Normand said.

"We may get additional evidence that would allow the DA to up-charge, or we may get additional evidence that may compel the DA to down-charge," Normand said. "But at this point in time, we believe that we have the evidence that fits the elements of manslaughter."

Sheriff defends delay in arrest

At Tuesday's press conference, Normand defended his department's decision not to immediately arrest Gasser Dec. 1, saying that "there is nothing that we have done in this case out of the ordinary, or that is unusual."

Making an immediate arrest could have tainted statements from witnesses or scared them off, he said. It's that strategy, Normand said, that led to one "key witness" coming forward on Saturday and several other witnesses being located through Monday night.

"Just as I pointed out on Friday, our suspicions that we were going to be able to get our hands around additional witnesses that would help in this case, actually came to fruition," Normand said.

The sheriff also said one witness at the scene the day of the shooting lied in stating that Gasser had exited his car, stood over McKnight, and shot again as McKnight was apologizing, Normand said. That witness' false statement, Normand continued, helped feed a social media frenzy in which thousands of commenters accused the sheriff's office of mishandling the case.

"We started Thursday afternoon with a witness who lied," Normand said. "A witness who said that Gasser got out of his car, popped caps through the wind shield of Joe McKnight's car, yanked him out of the car and popped him again while he was on the ground, (Gasser) saying that he had voted for Donald Trump and that he was going to show him. And we were off and running."

Normand said that witness "told three different stories within the same hour."

"Shame on that individual," he said. "And that started something going down a path that we collectively should be ashamed of ourselves."

Normand said some of the witnesses have provided statements that do not square with the statement Gasser gave to investigators. None of the witnesses were able to give any statements either corroborating or contradicting Gasser's statement Thursday evening, Normand said.

Speaking further at Tuesday's press conference, Normand said that the department has pursued "hundreds of cases" involving people known to have committed crimes but who are not arrested immediately "because of strategic reasons in our investigation." Normand pointed to that strategy as a key factor in Gasser's arrest for manslaughter, that allowed investigators to procure around 12 hours of statements Thursday evening without a lawyer present and "lock him in" on a story.

"Our arrest is only as good as a prosecution," Normand said. "We accomplish nothing if we make an arrest and we can't put ourselves in the best posture to reach a successful prosecution."

"Justice has no time limit," Normand continued. "Justice is not a sprint. It is a marathon. These investigations are marathons."

Through Gasser's cooperation, Normand said detectives were even given consent to search Gasser's home without first establishing probable cause. Normand said Gasser was in the middle of a three-and-a-half hour interview with investigators while Normand was giving a press conference last Friday, he said.

Normand said investigators conducted over 160 interviews in the case from Thursday to Monday night, even as the department dealt with a shooting that wounded a deputy Saturday morning in Metairie and the killing of a 10-month-old boy later that evening. Investigators also identified over 260 people that the sheriff's office had an interest in contacting based on license plate-recognition camera hits, and talked to over 70 businesses in an attempt to retrieve surveillance video, Normand said.

He continued Tuesday saying that sheriff's office conducted several crime-scene reenactments with the Jefferson Parish Coroner's Office over the weekend, and held multiple consultations with the coroner's office, the district attorney's office, and other "seasoned prosecutors."

Normand reiterated Tuesday that a claim of self-defense by Gasser is likely. The sheriff said a rush to make an arrest before collecting more evidence -- particularly witness statements -- could possibly have eroded the case against Gasser once the district attorney's office filed charges.

"In this state, whether we like it or not, we have very forward-leaning, stand-your-ground, self-defense, justifiable homicide laws, however you want to refer to it," Normand said. "That creates for us an obligation to make sure that we get it right."

Correction: An earlier version of this story said Ronald Gasser drove an Infinity vehicle. The brand is Infiniti.